body, html, .content, .black{
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}
.content {
  background-image: url('./background.jpg');
  background-size: 100% 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  top: 0;
  z-index: 10;
  left: 0;
}
.black{
  background-color: rgba(0, 0, 0, 0.6);
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}
.layui-btn-container button {
  margin: 26px 0;
}